Known in the art is a method for performing microoperations on cells, comprising the steps of securing a cell by means of a micro suction cap and introducing a microinstrument into the cell. The cell is pierced from the side opposite to the place where it is secured (cf., for example, P. Fonbruhn, Metody Mikromanipulyatsii, Inostrannaya Literature, Moscow, pp. 147-149, 1951, in Russian).
The cell membrane is extremely tough and resilient, and cannot be pierced at once by a touch of the sharp tip of the microinstrument, but is punctured only after a substantial deformation of the cell portion to be pierced and of the whole cell. As a result the cell is seriously injured.
Moreover, large deformation of the cell during the piercing process can lead to membrane rupture and subsequent ejection, and the loss of cytoplasm due to the general increase of the intracellular pressure. In some cases even organelles can be displaced in relation to one another.
Ejection of cytoplasm results in upset of the balance between the intracellular matter and the environment, and the cells which have been operated on become less viable.
Also known in the art is a method for performing microoperations on cells, which is a method of nuclei transplantation, comprising the steps of extracting a nucleus from the recipient cell and transplanting it into the donor cell whose own nucleus had been removed.
This procedure involves two introductions of a microinstrument into a cell: the first time to remove the nucleus and the second time to place another nucleus. The cell is, therefore, injured twice.
The number of successful operations is, as a rule, rather low (cf., for example, M. U. Koras, Instrumentation for the Transplantation of Nucleoli, Journal of the Franklin Institute, 262, 407-411, 1956).
Known in the art is a device for performing microoperations on cells, comprising a microinstrument placed in a holder rigidly connected to a mobile tool of a three-way micromanipulator, and a micro suction cup fitted on another micromanipulator intended to secure the cell to be operated on (cf., for example, French Patent No. 1,085,965 published in 1965).
This device has a rather complicated system of manipulator control and relatively low productivity during microoperations, since the operation of two micromanipulators has to be matched. In addition it is expensive and can still damage the cell when piercing it. The cell is still more damaged because of the vibration of the micro suction cup and microinstrument. Since the cell attached to the micro suction cup is sufficiently resilient, the microinstrument can be broken in an attempt to pierce the cell.